Nearly every high-voltage equipment prior to delivery to the customer will undergo a test related to C and tan delta for a final quality control. Such tests are in general made at a frequency for which the equipment is designed. The reasons for the tests are firstly that too high losses (= high tan delta) may cause a breakdown or, secondly, the manufacturer of a specific equipment knows the typical magnitudes which can be tolerated and which provide information about the quality of newly manufactured equipment, and these measurements can also serve for a comparison with later preventive measurements.

Such tests are in general made in dependence of the test voltage applied; both magnitudes, capacitance and dissipation factor shall be essentially constant with increasing voltage, as insulation systems are linear systems and any „tip-up“ of the tand with voltage level, called „ionisation knee“, is a preliminary indication of partial discharges in the system which can lead to a failure of the insulation system.

TG1
Automatic + manual mode,
tan delta uncertainty 10-5

TG3
Automatic measuring bridge.
tan delta uncertainty 10-5

TG4
Universal c- and dissipation
factor measuring bridge

FT12
Automatic capacitence and power factor field test set with 12kV / 200mA Supply.

Optional Suplies:
Oil Test Cell
Resonating Inductor

Tan delta simulators
Tan delta calibration standards